code: def _force_list(axis):
      if hasattr(axis, "__iter__"):
          return axis
  
      return [axis]
  
imports: from __future__ import absolute_import
  from .function_bases import *
  from six.moves import reduce
  import numpy
  import nnabla
label_desc: Use image node_id 2 for calling a global function with example usage: _force_list(axis) and returns: list, axis